I've searched the forums and found that they can have an IT earthing arrangement. My brother lives there and has been asking me questions about his newly purchased house. I'm under the impression that all work has to be done by registered electricians - maybe this explains the general state of disrepair many Norwegian homes seem to be in.
The (old) 230V IT system apart, the modern TN system (European standard 230/400V) will not differ much from the rest of Europe.
Sockets: Schuko, standard Boxes: 60 mm, round continental standard Cables: Sizes and colours, same as found in all of Europe today. Cable types: Unique to Norway, not that they differ much from those of any other country. MCB's: Standard type, found in all of Europe.
[This message has been edited by C-H (edited 04-12-2006).]